1. Field of the Invention
The invention relates to a cycloidal speed reducer having axially adjustable pin-mounted rollers to reduce backlash or free-play between components of the device.
2. Description of the Prior Art
Cycloidal speed reducers are known in the art for applications requiring transmission of rotational movement or torque at selected, varying speed reductions. Devices of this type include an eccentrically mounted, multilobed cam that orbits in response to input from a drive shaft within a plurality of circularly disposed pin-mounted rollers. The orbiting action of the cam imparts at reduced speed the torque from the input shaft to an output shaft of the device.
An example of a device of this type with which the invention of this application finds particular utility is described in U.S. Pat. No. 3,998,112 issued Dec. 21, 1976.
In prior art devices of this type, to provide a desired, accurate ratio of speed reduction it is necessary to reduce the free-play or backlash between components of the device. Most critical in this regard is the contact between the pin-mounted rollers and the multilobed cam surface in rolling contact therewith. Contact between these components is conventionally provided by individually adjusting each pin and associated roller relative to the interacting cam surfaces. This practice is cumbersome and time consuming and is used only in applications where accurate ratios of speed reduction are required Otherwise, the free-play between these components and the resulting inaccuracy of the ratio of speed reduction is tolerated.